判断资源存在与否如判断一个drawable的图片存在及通过id加载图片

留下来以后备用！

int i= getResources().getIdentifier("icon", "drawable", getPackageName()) ;
if(i>0)
{Log.i("aa","aa");}
else
{Log.i("vbv","aa");}

或者

int resID = getResources().getIdentifier("org.loveandroid.androidtest:drawable/gallery_photo_1",null,null);

int resID = getResources().getIdentifier("org.anddev.android.testproject:drawable/bug",null, null);
// or
int resID = getResources().getIdentifier("bug","drawable", "org.anddev.android.testproject");

第一个参数其实

full_package:type/filename_without_ending是这种格式 然后其他的可以为null

Java代码

1. int idFlag = getResources().getIdentifier(
2. getPackageName() + ":drawable/flag",
3. null, null);
4. // 或是
5. int idFlag = getResources().getIdentifier(
6. "flag", "drawable", getPackageName());

int idFlag = getResources().getIdentifier(         getPackageName() + ":drawable/flag",          null, null);   // 或是   int idFlag = getResources().getIdentifier(         "flag", "drawable", getPackageName());  

Java代码

1. var Drawable[] dw = new Drawable[10];
3. for (int i = 1; i <= 10; i++) {
4. int id = getResources().getIdentifier(
5. "flag" + i,
6. "drawable", getPackageName());
7. dw[i-1] = getResources().getDrawable(id);
8. }

var Drawable[] dw = new Drawable[10];     for (int i = 1; i <= 10; i++) {     int id = getResources().getIdentifier(                       "flag" + i,                        "drawable", getPackageName());     dw[i-1] = getResources().getDrawable(id);   }

用反射发 可以得到 所有的资源

Java代码

1. private void
2. _DumpAllResourceIDs(Class<?> classType)
3. throws IllegalArgumentException {
4. Field[] fIDs = classType.getFields();
6. try {
7. for (int i = 0; i < fIDs.length; i++) {
8. Field fld = fIDs[i];
9. int nID = fld.getInt(null);
10. Log.d("dbg",
11. classType.getSimpleName() + " " +
12. i + ": " +
13. fld.getName() + "=" +
14. nID);
15. }
16. } catch (Exception e) {
17. throw new IllegalArgumentException();
18. }
19. }

private void      _DumpAllResourceIDs(Class<?> classType)        throws IllegalArgumentException {     Field[] fIDs = classType.getFields();                try {       for (int i = 0; i < fIDs.length; i++) {         Field fld = fIDs[i];         int nID = fld.getInt(null);         Log.d("dbg",           classType.getSimpleName() + " " +            i + ": " +            fld.getName() + "=" +           nID);       }     } catch (Exception e) {       throw new IllegalArgumentException();     }   }  

Java代码

1. import java.lang.reflect.Field;
2. ...
3. _DumpAllResourceIDs(R.layout.class);
4. _DumpAllResourceIDs(R.drawable.class);

import java.lang.reflect.Field;   ...     _DumpAllResourceIDs(R.layout.class);     _DumpAllResourceIDs(R.drawable.class);  

结果

Java代码

1. R$layout 0: main=2130903040
2. R$layout 1: small_spinner_dropdown_item=2130903041
3. R$drawable 0: icon=2130837504